1. Field of the Invention
The present invention relates generally to construction schedules and simulations, and in particular, to a method, apparatus, system, and article of manufacture for simulating a construction schedule based on a playback profile.
2. Description of the Related Art
Creating construction schedules is difficult. Many variables must be taken into account: owner requirements, budget, site conditions, construction methods, subcontractor availability, labor regulations, weather conditions, productivity rates, equipment needed, materials needed, staging areas, safety considerations, and so on. To compound the problem, these variables interact in complex ways. A faster construction method might be more expensive. Dangerous site conditions might require improved safety measures. This means that schedulers need good analytic tools to help them visualize the schedule, so that they can see how this welter of interacting variables will impact the schedule.
One analytic tool that has been developed in the last few years is schedule playback, aka schedule simulation. The schedule's activities are connected to three-dimensional (3D) model objects. The schedule is then simulated (played back): the model objects are displayed in the order determined by the schedule. This helps users see how the building process will unfold over time. Unfortunately, schedule simulation has been of limited value. It can help communicate the schedule (particularly to owners) but it hasn't been of much help in building, editing and managing schedules.
The problem is that simple schedule simulation treats all model objects equally: the erection of structural steel is given no more special treatment than the installation of furniture. However, the equal treatment of all model objects is clearly not the case in real life: some aspects of the schedule (e.g. critical path activities) are more important than others.
To better understand the above problems, a description of prior art schedule simulation may be useful. Two exemplary prior art products perform schedule simulation: the AUTODESK NAVISWORKS TIMELINER simulation software and SYNCHRO SOFTWARE's SYNCHRO PRO scheduling and construction project management software.
The AUTODESK NAVISWORKS TIMELINER simulator software lets the user import a schedule and associate schedule activities with model objects. Then, the schedule can be played back. The default simulation is a simple buildout: objects are shown when the schedule mandates them. If desired, the user can create custom “Task Types” that specify different appearances (prebuild, build and postbuild) for schedule activities. Users have the ability to manually create custom task types and then manually select desired schedule activities and finally assign those task types to the schedule activities. Such a process might be fine for a small schedule, but is untenable for a schedule containing hundreds or thousands of activities (as many construction schedules do). Moreover, Task Type assignments for a model/schedule pair are completely specific to that pair: they cannot be ported to another model/schedule pair.
The SYNCHRO PRO software is largely similar to the TIMELINER simulator. It allows the user to associate selected model objects with schedule activities, and to then play back the schedule. It has a concept of “Use Profile” which is similar to the above described Task Type. As with the TIMELINER simulator, the Use Profile specifies prebuild, build and postbuild appearances for a schedule activity's model objects. By default, four Use Profiles are provided: one each for Install, Maintain, Remove and Temporary tasks. Further, the user may add and use custom Use Profiles. However, such an addition and use of custom profiles would be manual and arduous: each time model objects are assigned to a schedule activity, the custom Use Profile would have to be manually selected. Moreover, there seems to be no way to easily reuse a set of Use Profile assignments on a new model/schedule pair.
In view of the above, what is needed is an easy, straightforward way to select key schedule elements (like critical path activities), and to make the schedule simulation highlight those key elements. In this manner, the scheduler can study the impact of the multitude of interacting construction variables on specific aspects of the schedule. Thereafter, the scheduler can build a more complete understanding of the entire schedule.